<div class="row">
  <ul class="nav nav-tabs">
    <li role="presentation" [class]="i==index?'active':''" *ngFor="let item of tabs;let index=index"><a href="javascript:void 0" (click)="i=index">{{item}}</a></li>

  </ul>


  <div [ngSwitch]="i">
    <div *ngSwitchCase="0">这是商品详情组件。。。。</div>
    <div *ngSwitchCase="1">这是评论区</div>
    <div *ngSwitchCase="2">这是帮助区</div>

    <div *ngSwitchDefault>...</div>
  </div>
</div>
